Boron trifluoride has found wide use as a catalyst for various reactions and has been proposed as a catalyst for additional reactions. Such reactions include hydrocarbon transfers (alkylations, cracking, isomerizations, polymerizations) and reactions involving functional groups (dehydration of alcohols, cyanation of olefins, conversions of aniline to diphenylamine, conversion of methylol to 4-methoxy-2-methyl-1-butene, reaction of ammonia and acrolein to form pyridine and reaction of sodium acetate and acetylene to form vinyl acetate). A drawback of the use of boron trifluoride is that it decomposes during reaction, preventing reuse and contributing boron and fluoride to either the product or an effluent stream, necessitating extra purification or recovery.
While attempts have been made to fix boron trifluoride to a polymer or inorganic support, these attempts have not produced a reusable boron trifluoride catalyst system practical for the wide variety of catalytic uses. For many particular reactions, a cocatalyst is provided with boron trifluoride to cause or enhance catalytic activity. Such cocatalysts have not, however, been used to retain the boron and fluoride values.
Specifically, the alkylation of aromatics such as the propylation of benzene is described in U.S. Pat. No. 2,425,839 to Schulze et al. (Aug. 19, 1947) using monohydric alcohol-boron trifluoride addition compounds. The oligomerization of alpha olefins such as the oligomerization of alpha-decene with adducts of monohydric alcohols and boron trifluoride is described in the following U.S. Pat Nos.: 3,780,128 Shubkin et al. (Dec. 18, 1973); 4,032,591 Cupples et al. (June 28, 1977); 4,045,507 Cupples et al. (Aug. 30, 1977); 4,045,508 Cupples et al. (Aug. 30, 1977); 3,957,664 Heilman et al. (May 18, 1977); 3,382,291 Brennan (May 7, 1968).
Additional BF.sub.3 gas feed and/or saturation of the hydrocarbon with BF.sub.3 are at least preferred by all three Cupples patents, the Brennan patent and the Shubkin patent.
Polyols such as ethylene glycol, propylene glycol and glycerol are discussed, but not exemplified, in several of these references as co-catalysts in place of monohydric alcohols.